Is this how it works?
Think of it as a little man inside armed with a codebook. You put in certain data - the bank account reference, the amount, your PIN. He uses the appropriate code for the time and day, give or take a few minutes. He generates a number.
Another little man at the bank end does the same thing, using the same information, and code book. If he gets the same number, then he lets you open the account or make the payment.
So I suppose the number is not exactly random, simply unpredictable, but repeatable given the same data entered at the same time.
Here's an experiment:
Borrow a second reader, and have two people enter the same information at the same time. Do they get the same number?
(They don't have to use the same card. The Barclays reader has its own card or you can use your ordinary card. It doesn't matter which, as long as you enter the appropriate number)
Last edited by: Cliff Pope on Thu 5 May 11 at 15:35
|